He is Harry Mark Christopher Judd (as said by him in the Wonderland DVD).

He is currently 22 and was born in Chelmsford, Essex on 23rd December 1985.

In the early days, he was described as the 'posh' member as his parents are well off and he attended Uppingham, a rather posh boarding school.
However, now he would be described as the 'sarcastic' one or the 'gay' one (thanks to his antics with the bassist of the band, Dougie Poynter).

Even though, Harry is straight and currently is with a girlfriend (of June 2008 this is written), he has somewhat a boy crush on fellow bandmate, Dougie Poynter. This was obvious in the Wonderland DVD under his profile where Harry admitted to "I like to hug Dougie", and is seen snuggling up to Dougie in the now famous PoynterJudd scene. He goes on to say "If anyone didn't know us in the band, they probably think we're a couple" (on his antics with Dougie in the pubic eye). Of course, it doesn't help that Harry always managed to come out with a quote that makes you think:
"I'm shagging Dougie"
"I'd go out with Dougie"
"Dougie looks really hot naked"
"I love you too, Dougie"
"Me and Doug had a sex scene in 'Just My Luck' but they took it out"
As well quoting, Harry and Dougie had gotten 'married' (seen on the 'I Wanna Hold You' DVD single under its own special section). Then later on in 2007, Harry 'proposed' to Dougie on stage during their tour and even later on, Harry told Dougie that he loves him (on Dougie's 20th birthday).
Harry is often seen staring at Dougie, or hugging him or doing something with the bassist, which had made people think the drummer could have a thing for Dougie - some call it brotherly/motherly love, but most think Harry just plainly fancies Dougie in some sense!
It was once known Harry had gay rumours in 2005 (possibly after the release of the Wonderland DVD) which he denied.

Harry grew up in a small family of an older brother (Thomas) and older sister (Katherine). His mother (Emma) and his father (Christopher) are still together.

Harry currently lives in North London in his own apartment which is in McFlyville, where Tom lives in a house (with his long term girlfriend), Dougie lives in an apartment which is in the same block as Danny's apartment and McFly's studio.

Dougie: "Harry smells like someone who sweats loads, doesn't wash for eight weeks - and then has a bath in onions!"
Harry: "I so do not!"